[–]water_badger 1 point 9 minutes ago
Most people have lots of feelings of sadness and anger that they have avoided letting themselves feel. Many parents have tried to encourage “positive” feelings and discourage “negative” feelings and culturally there is often a stigma against being angry or sad.
When you hear a baby crying it viscerally reminds you of feelings that you are trying to avoid through various distractions. You feel irritation at the baby for derailing this activity and especially if you are avoiding feeling angry these angry feelings can also be projected onto the baby.